Detection of damaged switched diplex filter

ABSTRACT

Methods, systems and computer readable media described herein may facilitate a detection of a damaged switched diplex filter. A CPE device may be equipped with one or more switches and one or more A/D converters. The one or more A/D converters may be utilized to monitor voltage at the one or more switches. In response to a detection of a rise in voltage above a threshold at a switch, upstream transmissions may be disabled at the CPE device.

CROSS REFERENCE TO RELATED APPLICATION

This application is a non-provisional application claiming the benefitof U.S. Provisional Application Ser. No. 62/517,248, entitled “Method toDetect Damage to Switched Diplex Filters Due to RF Port Surge Events,”which was filed on Jun. 9, 2017, and is incorporated herein by referencein its entirety.

TECHNICAL FIELD

This disclosure relates to a detection of damaged switched diplexfilters.

BACKGROUND

The DOCSIS 3.1 standard now allows for different frequency bands to beused for Upstream (US) and Downstream (DS) transmission. Most cableplants in use today have a 42/54 MHz split, meaning that US can be up to42 MHz and the DS frequencies begin at 54 MHz. In order to provide moreupstream bandwidth to customers, DOCSIS 3.1 allows for 42/108, 85/108,and 204/258 MHz diplexer splits. It is desirable to be able to deploy amodem today that works in existing 42/108 MHz plant, and be able toelectronically upgrade that modem in the field to work as a 204/258 MHzunit when a cable plant is upgraded. In order to do that, 2 diplexfilters may be included in the product, and the product may utilizesolid state RF switches to select a diplex filter. The problem with thistechnology is that the switches themselves are susceptible to lightningsurge events. In testing, it is quite common for an RF switch to bepartially damaged in such a way that it still passes a signal. Damage tothe switch of this type has consequences, and in this application theywould produce harmonics in the Downstream band which violated the DOCSISspecifications, and would affect other devices on the cable plantcausing outages.

Therefore, a need exists for improving methods and systems for detectingdamaged switches.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example network environmentoperable to facilitate a detection of a damaged switched diplex filter.

FIG. 2 is a block diagram illustrating an example CPE device operable tofacilitate a detection of a damaged switched diplex filter.

FIG. 3 is a flowchart illustrating an example process operable tofacilitate a detection of a damaged switched diplex filter.

FIG. 4 is a block diagram of a hardware configuration operable tofacilitate a detection of a damaged switched diplex filter.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

It is desirable to improve upon methods and systems for detectingdamaged switches. Methods, systems and computer readable media describedherein may facilitate a detection of a damaged switched diplex filter. ACPE device may be equipped with one or more switches and one or more A/Dconverters. The one or more A/D converters may be utilized to monitorvoltage at the one or more switches. In response to a detection of arise in voltage above a threshold at a switch, upstream transmissionsmay be disabled at the CPE device.

FIG. 1 is a block diagram illustrating an example network environment100 operable to facilitate a detection of a damaged switched diplexfilter. In embodiments, a CPE device 105 may include one or moreswitched diplex filters. A CPE device 105 may include a modem, a STB(set-top box), a multimedia gateway, or other device configured toreceive downstream communications from an upstream network and totransmit upstream communications to the upstream network. For example, aheadend 110 may provide one or more services (e.g., video service(s),data service(s), voice service(s), etc.) to one or more CPE devices 105.The headend 110 may route communications between one or more CPE devices105 and a wide-area network (WAN) 115. In embodiments, the one or moreCPE devices 105 may communicate with the headend 110 through a node 120,wherein the one or more CPE devices 105 are configured to communicatewith the node 120 through a transmission line 125 (e.g., RF (radiofrequency) cable, coaxial cable, etc.).

In embodiments, a CPE device 105 may include a tuner having one or moreA/D (analog-to-digital) converters. The A/D converters may be used tomonitor current draw on one or more switches (e.g., RF switches) of theCPE device 105. For example, the A/D converters may be used as a batterycharging monitor.

In response to a surge event, such as a lightning surge, currentconsumption at a switch may increase. In embodiments, the CPE device 105may monitor equipment for voltage increases resulting from surge events,and the CPE device 105 may disable upstream transmissions in response toan identified event.

FIG. 2 is a block diagram illustrating an example CPE device 105operable to facilitate a detection of a damaged switched diplex filter.In embodiments, a CPE device 105 may include a first diplex filter 205,a second diplex filter 210, a US (upstream) switch 215, a DS(downstream) switch 220, and a tuner 225. The tuner 225 may include abattery backup 230 and a resistive divider 235.

In embodiments, a CPE device 105 may be equipped with a battery back up(BBU) input 230 at a tuner 225, a current sense resistor at a US switch215, and a current sense resistor at a DS switch 220. A resistivedivider 235 may be used to reduce signals (e.g., 3.3V signals) to acorrect operating range of the BBU 230 (e.g., 1.3V). Firmware may readthe BBU 230 voltages, and display them to a command line interface.These measurements may be used to detect a rise in voltage by athreshold margin. It should be understood that the threshold voltagemargin may vary for each switch. For example, the threshold voltagemargin may be set at 9 mV for the DS switch 220 and 6 mV for the USswitch 215. The values may be re-read every few minutes and if a shiftin the voltage reading is detected, then an alert may be created for theuser and/or the MSO (multiple systems operator), and any furtherupstream transmissions may be disabled in response. This will preventthe damaged unit from negatively impairing other user equipment on theplant.

FIG. 3 is a flowchart illustrating an example process 300 operable tofacilitate a detection of a damaged switched diplex filter. The process300 can start at 305 where a voltage at a battery backup input of a CPEdevice 105 of FIG. 1 is read. For example, a voltage at a battery backup230 of FIG. 2 may be read and displayed at a command line interface.

At 310, a determination may be made whether the voltage read at thebattery backup is greater than a threshold voltage. For example, thevoltage read at the battery backup may be checked against an expected orhistorical voltage associated with the battery backup. In embodiments,the battery backup may be associated with a predetermined thresholdmargin, and if the voltage read at the battery backup is higher than theexpected or historical voltage by a margin that is greater than thepredetermined threshold margin, a determination may be made that thevoltage is greater than the threshold. If the determination is made thatthe voltage is not greater than the threshold, a next reading of avoltage at the battery backup input may be made at 305.

If, at 310, the determination is made that the voltage read at thebattery backup input is greater than the threshold, the process 300 mayproceed to 315. At 315, an alert indicating the voltage rise may beoutput. For example, the alert may be output to a user or MSO.

At 320, upstream transmissions may be disabled. For example, the CPEdevice 105 may disable further upstream transmissions.

FIG. 4 is a block diagram of a hardware configuration 400 operable tofacilitate a detection of a damaged switched diplex filter. The hardwareconfiguration 400 can include a processor 410, a memory 420, a storagedevice 430, and an input/output device 440. Each of the components 410,420, 430, and 440 can, for example, be interconnected using a system bus450. The processor 410 can be capable of processing instructions forexecution within the hardware configuration 400. In one implementation,the processor 410 can be a single-threaded processor. In anotherimplementation, the processor 410 can be a multi-threaded processor. Theprocessor 410 can be capable of processing instructions stored in thememory 420 or on the storage device 430.

The memory 420 can store information within the hardware configuration400. In one implementation, the memory 420 can be a computer-readablemedium. In one implementation, the memory 420 can be a volatile memoryunit. In another implementation, the memory 420 can be a non-volatilememory unit.

In some implementations, the storage device 430 can be capable ofproviding mass storage for the hardware configuration 400. In oneimplementation, the storage device 430 can be a computer-readablemedium. In various different implementations, the storage device 430can, for example, include a hard disk device, an optical disk device,flash memory or some other large capacity storage device. In otherimplementations, the storage device 430 can be a device external to thehardware configuration 400.

The input/output device 440 provides input/output operations for thehardware configuration 400. In one implementation, the input/outputdevice 440 can include one or more of a network interface device (e.g.,an Ethernet card), a serial communication device (e.g., an RS-232 port),one or more universal serial bus (USB) interfaces (e.g., a USB 2.0port), one or more wireless interface devices (e.g., an 802.11 card),and/or one or more interfaces for outputting video and/or data servicesto a client device (e.g., television, STB, computer, mobile device,tablet, etc.). In embodiments, the input/output device can includedriver devices configured to send communications to, and receivecommunications from one or more networks (e.g., WAN 115 of FIG. 1)through a headend 110 of FIG. 1 and node 120 of FIG. 1.

Those skilled in the art will appreciate that the invention improvesupon methods and systems for detecting damaged switches. Methods,systems and computer readable media described herein may facilitate adetection of a damaged switched diplex filter. A CPE device may beequipped with one or more switches and one or more A/D converters. Theone or more A/D converters may be utilized to monitor voltage at the oneor more switches. In response to a detection of a rise in voltage abovea threshold at a switch, upstream transmissions may be disabled at theCPE device.

The subject matter of this disclosure, and components thereof, can berealized by instructions that upon execution cause one or moreprocessing devices to carry out the processes and functions describedabove. Such instructions can, for example, comprise interpretedinstructions, such as script instructions, e.g., JavaScript orECMAScript instructions, or executable code, or other instructionsstored in a computer readable medium.

Implementations of the subject matter and the functional operationsdescribed in this specification can be provided in digital electroniccircuitry, or in computer software, firmware, or hardware, including thestructures disclosed in this specification and their structuralequivalents, or in combinations of one or more of them. Embodiments ofthe subject matter described in this specification can be implemented asone or more computer program products, i.e., one or more modules ofcomputer program instructions encoded on a tangible program carrier forexecution by, or to control the operation of, data processing apparatus.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, or declarative orprocedural languages, and it can be deployed in any form, including as astand-alone program or as a module, component, subroutine, or other unitsuitable for use in a computing environment. A computer program does notnecessarily correspond to a file in a file system. A program can bestored in a portion of a file that holds other programs or data (e.g.,one or more scripts stored in a markup language document), in a singlefile dedicated to the program in question, or in multiple coordinatedfiles (e.g., files that store one or more modules, sub programs, orportions of code). A computer program can be deployed to be executed onone computer or on multiple computers that are located at one site ordistributed across multiple sites and interconnected by a communicationnetwork.

The processes and logic flows described in this specification areperformed by one or more programmable processors executing one or morecomputer programs to perform functions by operating on input data andgenerating output thereby tying the process to a particular machine(e.g., a machine programmed to perform the processes described herein).The processes and logic flows can also be performed by, and apparatuscan also be implemented as, special purpose logic circuitry, e.g., anFPGA (field programmable gate array) or an ASIC (application specificintegrated circuit).

Computer readable media suitable for storing computer programinstructions and data include all forms of non-volatile memory, mediaand memory devices, including by way of example semiconductor memorydevices (e.g., EPROM, EEPROM, and flash memory devices); magnetic disks(e.g., internal hard disks or removable disks); magneto optical disks;and CD ROM and DVD ROM disks. The processor and the memory can besupplemented by, or incorporated in, special purpose logic circuitry.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyinvention or of what may be claimed, but rather as descriptions offeatures that may be specific to particular embodiments of particularinventions. Certain features that are described in this specification inthe context of separate embodiments can also be implemented incombination in a single embodiment. Conversely, various features thatare described in the context of a single embodiment can also beimplemented in multiple embodiments separately or in any suitablesubcombination. Moreover, although features may be described above asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multitasking and parallel processingmay be advantageous. Moreover, the separation of various systemcomponents in the embodiments described above should not be understoodas requiring such separation in all embodiments, and it should beunderstood that the described program components and systems cangenerally be integrated together in a single software product orpackaged into multiple software products.

Particular embodiments of the subject matter described in thisspecification have been described. Other embodiments are within thescope of the following claims. For example, the actions recited in theclaims can be performed in a different order and still achieve desirableresults, unless expressly noted otherwise. As one example, the processesdepicted in the accompanying figures do not necessarily require theparticular order shown, or sequential order, to achieve desirableresults. In some implementations, multitasking and parallel processingmay be advantageous.

We claim:
 1. A method comprising: reading a voltage at a battery backupinput; determining that the voltage is greater than a threshold voltage,wherein the battery backup input is associated with a first switch and asecond switch, wherein the voltage read at the battery backup input isassociated with either the first switch or the second switch, whereinthe first switch is associated with a first threshold voltage, andwherein the second switch is associated with a second threshold voltage;outputting an alert indicating a voltage rise; and disabling upstreamtransmissions.
 2. The method of claim 1, wherein the first thresholdvoltage and the second threshold voltage comprise different values. 3.An apparatus comprising: a battery backup input; and one or more modulesthat: read a voltage at the battery backup input; determines that thevoltage is greater than a threshold voltage; outputs an alert indicatinga voltage rise; and disables upstream transmissions; and a first switchand a second switch, wherein the voltage read at the battery backupinput is associated with either the first switch or the second switch,wherein the first switch is associated with a first threshold voltage,and wherein the second switch is associated with a second thresholdvoltage.
 4. The apparatus of claim 3, wherein the first thresholdvoltage and the second threshold voltage comprise different values. 5.One or more non-transitory computer readable media operable to executeon one or more processors, the computer readable being operable to causethe one or more processors to perform the operations comprising: readinga voltage at a battery backup input; determining that the voltage isgreater than a threshold voltage, wherein the battery backup input isassociated with a first switch and a second switch, wherein the voltageread at the battery backup input is associated with either the firstswitch or the second switch, wherein the first switch is associated witha first threshold voltage, and wherein the second switch is associatedwith a second threshold voltage; outputting an alert indicating avoltage rise; and disabling upstream transmissions.
 6. The one or morenon-transitory computer readable media of claim 5, wherein the firstthreshold voltage and the second threshold voltage comprise differentvalues.